Modern automotive light modules typically use a filament bulb as their light source. While such modules have a long and successful history, filament bulbs consume a large amount of power and have a relatively short life. In an attempt to overcome these shortcomings, others have proposed to utilize LED light sources to replace the filament bulbs since LED's consume significantly less power and have a long life span.
Unfortunately, LED solutions also have their drawbacks. In particular, automotive light assemblies utilizing LED light sources typically use a large number LED's, typically eight or more, which thus requires increasing amounts of power over a single LED bulb. Furthermore, these light modules using LED light sources suffer from poor efficiency, that is, the amount of original light from the light source which is actually directed outwardly away from the vehicle to illuminate the surrounding area.
In some applications, trough reflectors have been used for LED light sources. However, these reflectors usually result in a wider horizontal spread of the light beam than is required or desired. While side walls have been proposed to cut down on the horizontal spread, such reflectors overly constrain the light distribution. Furthermore, the use of side walls results in wasted light which is beyond the driver's field of vision. Additionally, the light collection efficiency of the trough reflector depends on its width, and the wider the trough the more horizontal the spread. Likewise, to collect a sufficient amount of light for a given width of the trough, numerous LED's must be placed at regular intervals along the trough axis. The use of multiple LED's increases the horizontal spread even further and also increases the amount of power consumed and the heat which must be dissipated.
Accordingly, there exists a need to provide a light assembly and trough reflector for a motor vehicle which can collect a sufficient amount of light, preferably from a single LED, while at the same time providing control over the horizontal spread as well as other beam pattern characteristics.